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| == Function == | | == Function == |
| [https://www.uniprot.org/uniprot/GTFC_STRMU GTFC_STRMU] Production of extracellular glucans, that are thought to play a key role in the development of the dental plaque because of their ability to adhere to smooth surfaces and mediate the aggregation of bacterial cells and food debris. | | [https://www.uniprot.org/uniprot/GTFC_STRMU GTFC_STRMU] Production of extracellular glucans, that are thought to play a key role in the development of the dental plaque because of their ability to adhere to smooth surfaces and mediate the aggregation of bacterial cells and food debris. |
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| == Publication Abstract from PubMed ==
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| Glucansucrase (GSase) from Streptococcus mutans is an essential agent in dental caries pathogenesis. Here, we report the crystal structure of S. mutans glycosyltransferase (GTF-SI), which synthesizes soluble and insoluble glucans and is a glycoside hydrolase (GH) family 70 GSase in the free enzyme form and in complex with acarbose and maltose. Resolution of the GTF-SI structure confirmed that the domain order of GTF-SI is circularly permuted as compared to that of GH family 13 alpha-amylases. As a result, domains A, B and IV of GTF-SI are each composed of two separate polypeptide chains. Structural comparison of GTF-SI and amylosucrase, which is closely related to GH family 13 amylases, indicated that the two enzymes share a similar transglycosylation mechanism via a glycosyl-enzyme intermediate in subsite -1. On the other hand, novel structural features were revealed in subsites +1 and +2 of GTF-SI. Trp517 provided the platform for glycosyl acceptor binding, while Tyr430, Asn481 and Ser589, which are conserved in family 70 enzymes but not in family 13 enzymes, comprised subsite +1. Based on the structure of GTF-SI and amino acid comparison of GTF-SI, GTF-I and GTF-S, Asp593 in GTF-SI appeared to be the most critical point for acceptor sugar orientation, influencing the transglycosylation specificity of GSases, that is, whether they produced insoluble glucan with alpha(1-3) glycosidic linkages or soluble glucan with alpha(1-6) linkages. The structural information derived from the current study should be extremely useful in the design of novel inhibitors that prevent the biofilm formation by GTF-SI.
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| Crystal Structure of Glucansucrase from the Dental Caries Pathogen Streptococcus mutans.,Ito K, Ito S, Shimamura T, Weyand S, Kawarasaki Y, Misaka T, Abe K, Kobayashi T, Cameron AD, Iwata S J Mol Biol. 2011 Feb 25. PMID:21354427<ref>PMID:21354427</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 3aic" style="background-color:#fffaf0;"></div>
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| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
